Process of producing alcohols from gasoline



Patented Aug. 2, 1932 EUQEINE E. AYERS, JR 033' PATENT caries SWARTHHOBE, PENNSYLVANIA, ASSIGl-NOR TO THE B. A. S.

COMP-ANY, 43F PHILADELPHIA, PENNSYLVANIA, A GOBPGMTION 01' DIELAWABE I IPBOUESE 03 PRODUCING ALGQHOLB FROM GASO y he wins.

M invention relates to processes for the pro notion of but 1 and amyl alcohols from gasoline derived om natural gas.

It is an object of the present invention to provide a process whereby type ordinarily employed -or the reduction by acet lation of commercial so vents for nitrocel ulose, may be synthesized from a relatively inexpensive source of raw material. A further object of my invention is to provide'a process wherein the byproducts have commercial value.

in the practice of my invention the source of the raw material, namely, gasoline ob tained from natural gas, is divided by rectification into certain fractions. The first fraction, composed of lower boiling hydrocarhens, is not utilized in the present invention, said low boiling hydrocarbons not being valuable for purposes of synthesis of alcohols that are sought by this process nor as a constituent in gasoline. The second and third fractions I use as a source of raw material in my process of forming alcohols, these two fractions respectively resulting in diflerent forms of alcohols in the final step of the process.

The rectification is accomplished by reusing isobutane during the separation of the first fraction. ll it is'desired to handle the butane and pentane fractions separately it is necessary to reflux normal butane while obtaining t e second fraction and to reflux normal pentane While obtaining the third fraction. (in the other hand, if it is desired to handle the butane and pentanes together, as for the purpose of reducing the number of rectifying columns in a continuous system, the refluxing of normal butane need not be carefully carried out but in every case nor- Incl pentane is refluxed to prevent the carrying over of higher boiling hydrocarbons.

The residue, alter the separation by either oi? these o erations 0f the three fractions above mentioned, comprises a useful form of gasoline, especially adapted to use as airplane fuel, as dry cleaners benzine, or as a solvent in the rubber industry. in accordance with my invention 1 can adjust the initial and end boiling points of this product to alcohols of the h Application filed September 24, m5. Serial at. 50,410.

meet trade requirements or specifications which may be imposed. The fractions which I have designated respectively as second and third are then subjected to. chlorination by eatingwith chlorine and the chlorine substitution roducts are converted by hydrolysis into t e desired alcohols as by means of processes set forth in co-pending applications hereinafter set forth.

In the first step of my process, natural, or

casinghead, gasoline is subjected to fractional distillation in a rectifier. I separate as a first fraction all those lighter hydrocarbons haying higher volatility which are not useful in gasoline and which do not form alcohols of the type herein contemplated. But while} prefer to use thesehydrocarbons for their fuel value in the preferred form of my invention, I merely suggest this as a convenience and do not intend that my invention shall be limited to such a procedure. The first frac; tion separated ofi is composed princi ally oi propane and'isobutane. The second motion separated ofi comprises principally normal butane; The third fraction contains chiefly pentane and isomers thereof. After the separation of the above mentioned fractions the residual liquid, is composed largely of hexane and its isomers with a small boiling hydrocarbons.

The fractions which I utilize for the purpose of makin alcohols are those which I have designate respectively as second and third above, that is, the fractions whi h may be designated as the butane and the pew tune fractions, it being understood that in each case the fraction is not composed of a pure substance but contains many sulystui'mes including isomers. The butane and pentane percent of higher fractions may then be treated in accordance with the succeeding steps of my process either separately or in mixture, Ill-treated separately the resulting alcohols are respectively butyl and amyl alcohols; if treated in Knisture, the butyl and amyl alcohols.

ln efiecting the above described separations of the gasoline into these fractions, the distillation may be run continuously or discontinuously, under a pressure that is high resulting alcohols are a mixture of pgints be accurately adjusted.

' so-calle by the series of steps enou h that condensation for purposes of recti cation reflux may be readily performed. Inasmuch as the boiling points of utane and pzntane at various pressures are well known,

ing shown in the Wilson & Bahlke chart appearing at pa e 116, of volume 16, No. 2, of Industrial and ngineering Chemistry, for February 1924, and in the chart appearing at page 32-001 National Petroleum News, for April 8, 1931, the pressure employed while distilling'ofi the normal butane and the pentane fractions can be chosen to suit the temperature of the condensing medium available. Even in summertime when condensers is not readily maintained low temperature, it will be ebserved that the pentane fraction may be distilled a gauge pressure of 25 lbs. per square inch at w ich its boiling point is in the neighborhood of 155 F. and the normal butane fraction may be distilled at a gage pressure in the neighborhood of 7 5 lbs. per square inch at WhlCh its boiling point is in the neighborhood of 140 F. When the normal butane fraction is collected separately from the pentane fraction, the reflux substance must contain butane, while the butane is being taken off, and must contain entane while the pentane is being takeno The rectification may be so conducted as to obtain practically ninety nine percent purity of the butane and pentane fractions but it is suflicient for the purposes of my process to obtain merely a ninety percent purity, this being satisfactory for the succeeding steps which I employ for the synthesis of alcohols.

The residue, com osed mainly of hexane and with traces 0 higher boiling hydrocarbons, has certain special uses in which its value is enhanced if its initial and end boilin The initia 11mg (point of the hexane residue (loosely may be lowered by leaving in the residue or introducing into it a relatively small quantity of pentane, and thus the imtial boiling point of the hexane residue may be adjusted over a range of temperatures.

The end boiling point may be adjusted by fractional distillation of the hexane residue in a rectifier to an extent sufiicient to se arate the hexane from the higher boiling ydrocarbons. In this way the initial and end boilmg points of a gasoline comprised almost wholl of hexane may be determined and aduste and thus a useful commercial article produced as a by-product of my process for {he production of alcohols from natural gasoine.

The butane and pentane fractions are then synthesized into corresponding alcohols. as set forth in co-pending applications hereinafter mentioned. Following the separation of the pentane fraction (which will be used by way of illustracooling water for o chlorine aaaaoaa tion) the pentane is chlorinated by the action of heat, as distinguished from the action of actinic rays, in order that the proportion of primary monochlorides produced will be relatively large, the process, and the apparatus for the practice thereof, disclosed in my Patent .No. 1,741,393 issued December 31, 1929. The chlorinated product thus obtained is then hydrolized to produce alcohols, preferably in accordance with the process disclosed in Patent No. 1,691,426 issued November 13, 1928, to myself and Erling H. Haabestad.

Alcohols so produced may be purified, preferably by extraction with water, as for exam le, by the method disclosed-in Patent No. 1, 16,957, issued June 11, 1929, to Erling H. Haabestad.

Thus, the chlorination of the butane and pentane may advantageously be effected by vaporizing those hydrocarbons and mixing them in excess, e. g. fifteen to twent parts of hydrocarbon vapor to one part 0 chlorine gas, and then causing the hydrocarbons and to react by raising the temperature of the mixture to a temperature between 600 F. and 700 F. Then the roducts of the chlorinating operation are, fore or after separation of the hydrochloric acid, subjected to rectification to recover unchlorinated h drocarbons as one product and chlorina hydrocarbons free of unchlorinated hydrocarbons as the other product. Unchlorinated hydrocarbons recovered from the product of the reaction and freed of hydrochloric acid may be returned to the chlorinating operation. The normal butane and entanes so chlorinated containan unusual y large proportion of primary monochlorides of those hydrocarbons.

And, the chlorine derivatives of normal butane and pentane, soproduced, are advantageously hydrolyzed to produce monohydric alcohols containing four to five carbon atoms by converting the chlorine derivatives into esters by heating them with water and a salt of a substantially water-insoluble fatty acid and then completing the hydrolyzation in one of two ways. The organic ester, for exam le, amyl oleate, may be heated with a hy rolyzing agent,-such as caustic soda, producing alcohol and soap. Or, the organic ester may be heated in the presence of water t ther with additional quantities of the ch orine derivatives and a suitable hydrolyzing agent, such as sodium hydroxide, in which case any soap formed reacts at once to restore or replace the organic ester, and

the organic ester, in a sense, acts as a catalyst to effect substitution of hydroxyl radicals for the chlorine atoms of the chlorine derivatives. In such of the chlorine derivative with the soap to produce the organic ester is rapid and complete in spite of the insolubility of the soap preferably in accordance with operations the reaction I I mousse in chlorine derivatives of hydrocarbons, because of the colloidal contact attained in the operations described; and the production of alcohol is relatively rapid and complete because'of the presence of the organic ester, and the product is unusually free of undesirable products because the pressures employed need not substantially exceed the pressures necessary to maintain the finalv products in liquid form at a temperature of 150 C. in a closed vessel.

And, the purification of the resulting butyl and amyl alcohols or a mixture of them is advantageously efiected by water extraction in which a continuous circulation of water is maintained, the water absorbing alcohol at one point of its circulation and alcohol being separated therefrom at another point of its circulation. In such an operation the water is circulated through a body of the crude alcohol and then passed to a still and then returned to the body of crude alcohol. In the still the alcohol-containing water is heated and the vapors contain more alcohol than can be dissolved in the water contained in the vapors. The vapors are condensed and separation of alcohol from water is made by gravity, the condensed Water containing whatever alcohol'it will dissolve being returned to the still and thus 'to' the body of crude alcohol. The alcohol may be dried by heating and the resulting va'pors returned to the condensing operation. The amyl and butyl alcohols are thus freed of such substances as amyl and butyl chlorides and hydrocarbons.

As a specific example of the practice of my invention I have started with 100 gallons of gasoline made from natural gas. Upon rectification it was found that 5 gallons were lost in the first fraction, composed of propane and isobutane. The second fraction, containing normal butane, amounted to 20 gallons; the pentane fraction amounted to 25 gallons; and the hexane residue amounted to gallons. This residue was of a quality and possessed of initial and end boiling points such as to make it suitable for airplane fuel. The butane and pentane fractions were each about 90 percent pure. After chlorination, the 20 gallons of butane yielded Q0 gallons of butyl chloride; and the 25 gallons of pentane yielded 24 gallons of amyl-chloride. These chlorides were respectively hydroly'zed and after purification yielded respectively 14 gallons of butyl of amyl alcohols.

More specifically, with respect to the following example of the production of amyl alcohols from pentanes, the chlorination of the character above described, by the action of heat in the absence of actinic rays and the absence of electric discharge, of a mixture of and 16 gallonslpentanes obtained from natural gasoline and living a boiling range from 28 C. to 36 C.-

gives a mixture of chlorides which is difiicult to analyze and contains the following substances 1n approximately the proportions indlcatedz mat-27% CHa'CHiCHrCHa'CIhCl l-chlorpcntane 15%-18% CHrCHrCHrCHCl-CH: 2-chlorpentane 7%10% CHz'CHrCHOl'CIIrCH; 3-cblorpentanc 11 14 cm CH: 4%c% GH'CHC1'CH: 2-chlor-3-methyl butane on. man-27% on-om-on, l -cblor-2-methyl butane onioi on= 4%7% /C Cl'CHg'CH; i'rchlor-2-methyl butane CH: and hydrolyzing of that mixture ofchlorides by hydrolysis of the character above de scribed in the presence of water and a salt of a substantially water-insoluble fatty acid, produces a mixture of amyl alcohols which is An important requirement of my process is so to regulate the rectification of the casing head gasoline as to separate the first fraction, (which contains undesirable propane and isobutane) with as small a content of desirable normal butane as possible. It is accordingly necessary to reflux isobutane at the beginning of the distillation in order that any normal butane which ma have been carried away in the vapors shall be recondensed and returned to the'liquid.

While I have described the application of my process to the synthesis of butyl and amyl alcohols from a specific grade of natural gasoline, I do not intend that mdy process shall be regarded as being limite to the specific example used as an illustration, but that it shall be regarded as covering all modifications or extensions thereof as fall within the hereinafter appended claims.

' What I claim as new and desire to secure by Letters Patent of the United States is: a

-1. In the manufacture of monohydric alcohols having four to five carbon atoms, the steps comprising chlorinating in vapor phase asaturated hydrocarbon obtained from natural gas and having four to five carbon atoms, by heating the hydrocarbon in the presence of chlorine gas and in the substantial absence of actinic rays and of electric discharge and thereby forming a chlorine derivative thereof containing a substantial proportion of primary monochloride, and hydrolyzing the resulting hydrocarbon chloride by heating in the presence of an aqueous alkaline agent and an ester of a substantially water-insoluble fatty acid and thereby forming corresponding monohydric alcohol of which a substantial proportion is primary normal alcohol.

2. In the manufacture of amyl alcohohthe steps comprising chlorin ating in vapor phase saturated pentanes obtained from natural gas, by heating the pentanes in the presence of chlorine gas and in the substantial absence of actinic rays and of electric discharge and thereby forming chlorine derivatives of the pentancs containing a substantial proportion of primary monochlorides of the pentanes, and hydrolyzing the resulting pentane chlorides by heating in the presence of an aqueous alkaline agent and an ester of a substantially water-insoluble fatty acid and thereby forming amyl alcohols of which a substantial proportion is primary normal amyl alcohol.

3. In the manufacture of butyl alcohol, the steps comprising chlorinating in vapor phase saturated normal butane obtained from natural gas, by heating the butane in the presence of chlorine gas and in the substantial absence of actinic rays and of electric discharge and thereby forming a chlorine derivative of the butane containing a substantial proportion of primary mono-chloride of butane. and. hydrolyzing the resulting butane chloride by heating in the presence of an aqueous alkaline agent and an ester of a substantially water-insoluble fatty acid and thereby forming butyl alcohol of which a substantial proportion is primary normal butyl alcohol.

In testimony whereof, I hate signed my name to this specification.

EUGENE E. A E-ES Saw 

